The conventional method for grinding work is well known by using the sand paper or sand cloth to complete. In the recent years, people in this field have invented a new structural grinding body by using the nylon fiber for grinding work. When this type of grinding body are at work, a large amount of rubbish would be generated and settled into the pores of the nylon fiber. But as the rotation of the grinding body continues, the centrifugal force generated by the rotating grinding machine would spin out all the rubbish from the grinding body, and thus no rubbish would be left on the grinding surface.
The conventional sand cloth or sand paper has a fine and well defined structure on the grinding surface. During the grinding process, a portion of the rubbish would build up on the grinding surface. The sand paper and sand cloth can not effectively remove the continuously generating rubbish. Therefore, as the grinding process continues, the effectiveness and grinding ability of the sand paper and sand cloth decreased. Due to the facts that the grinding body made of nylon fiber has many advantages and the strength of the nylon fiber is far better than the conventional sand cloth or sand paper, the nylon fiber grinding body has gradually replaced the traditional sand paper or sand cloth. Also the grinding body can be mounted on a turntable that is screwed on a handheld grinding machine, so that the high speed turning motion of the handheld grinding machine can drive the grinding body to rotate and effectively and efficiently provide a better and faster work.
In accordance with the above description, the conventional nylon fiber grinding wheel 10 (as shown in FIG. 1) comprises a nylon fiber grinding plate 11, and a turntable 12 is attached to the nylon fiber grinding plate 11 by a gluing agent A, wherein the turntable 12 has a screw hole 13 centrally provided thereon for a turning axle 21 of the handheld grinding machine to pass through. The nylon fiber grinding wheel 10 is screwed on the turning axle 21 of the handheld grinding machine by a locking cylinder 22. When the handheld grinding machine is turned on, the turning axle 21 of the handheld grinding machine would drive the nylon fiber grinding plate to rotate for grinding purpose.
However, during the grinding process, the nylon fiber grinding wheel 10 and the grinding surface would generate a torque force therebetween. The ability to resist the torque force is limited by the resistance force between the gluing agent A and the turntable 12 because that is the weakest part of the connection. As the grinding speed increases, the torque force generated between the nylon fiber grinding wheel 10 and the grinding surface would also increase. When the torque force exceeds the resistance force between the gluing agent A and the turntable 12, the turntable 12 would not be able to stay attached to the nylon fiber grinding plate 11, and thus the nylon fiber grinding plate 11 would be separated from the nylon fiber grinding wheel 10 (at this time, the turntable 12 is still screwed on the turning axle 21 of the handheld grinding machine). In view of the above disclosure, we know that the conventional nylon fiber grinding wheel 10 is only attached to a flat bottom surface of the turntable 12 by the gluing agent A. The resistance force generated by this type of connection is only adequate for grinding work at slower speed rotation below 5,000 rpm. When the turning speed is more than 5,000 rpm, there is a great chance that the resistance force would be unable to withstand the torque force and cease the grinding process.
As shown in FIG. 2, another type of conventional turntable 30 is illustrated. The turntable 30 has radially provided a plurality of through holes 31 on its surface. When the turntable 30 is attached to the nylon fiber grinding plate 11 by the gluing agent A, the gluing agent A would fill the contact surface between the turntable 30 and the nylon fiber grinding plate 11, and that a portion of the gluing agent A would also fill the plurality of through holes 31 of the turntable 30. The gluing agent A which fills the through holes 31 would create a greater bonding ability between the turntable 30 and the nylon fiber grinding plate 11 (as shown in FIG. 3). When the contact area increases, the turntable 30 and the gluing agent A would also increase the resistance force that enables the nylon fiber grinding plate being driven to rotate at a higher speed between 5,000 rpm to 7,000 rpm during grinding operation.
The truning speed of the grinding machine and the work processing speed are in direct proportion. The higher the grinding machine can turn, the faster the grinding work can be completed. All the above described conventional nylon fiber grinding plate can only be worked at an ideal turning speed of 7,000 rpm and under. What if we can increase the turning speed of the grinding machine to a degree that the nylon fiber grinding plate and the turntable can handle? Then for sure we can speed up the grinding process and achieve better grinding performance.